1. Field of the Invention
This invention relates to a driving system for a mobile robot, particularly to a driving system for a mobile robot that can effectively supply drive voltage to electric motors installed at joints of the robot.
2. Description of the Related Art
Generally, a mobile robot moves when drive voltage is supplied to electric motors from an on-board battery (power source). One example thereof is a technique taught by Japanese Laid-Open Patent Application No. Hei 11 (1999)-48170. The reference discloses a driving system for a legged mobile robot having two leg links connected to a body through hip joints and each connected by a knee joint, electric motors installed at the joints, a battery (power source) installed in the body and driving circuits that supplies voltage from the battery through power lines to the motors to drive them. When the remaining capacity of the battery is small, the system discriminates that the robot is likely to fall down and controls the robot operation to lower its center of gravity. In the aforesaid prior art, the power lines connecting the battery to some motors are arranged across the associated joints.
Considering the possibility of, for instance, electric leakage due to breakage of the power line in the joint, it is preferable to drive the motors at low voltage. On the other hand, it is necessary to drive the motors at high voltage to increase their rotational speed for controlling the robot to move at a high speed. Thus, the above two demands are contradictory.